1. Field of the Invention
This invention relates generally to the field of physical exercise equipment and, particularly, to a press arm for performing upper body exercises.
2. Prior Art
The bench press has long been a popular exercise for developing the muscles of the upper body. This exercise is traditionally performed in a supine position on a bench using a barbell. Within the last few decades, exercise machines have been developed with pivoting press arms coupled to a stack of weights that allow the operator to perform exercises from a seated position. Typically, the seat of the machine is adjustable so that shoulder press, incline press, chest press, and decline press exercises can all be performed using the same press arm.
A conventional press arm is pivotally attached to the frame of an exercise machine and has a pair of fixed handles for use by the operator. The operator pushes the press arm directly away from the torso during performance of the exercise. However, it has been found that a more thorough exercise can be achieved if the operator is able to move his or her arms inwardly (in what is commonly referred to as a "butterfly" or "fly" motion) as the press arm is pushed outwardly. Exercise machines have been developed to afford this additional component of movement. For example, U.S. Pat. No. 5,437,589 discloses such a machine for performing shoulder, incline, chest and/or decline press exercises. While the apparatus disclosed in the aforementioned patent provides a near optimal upper body exercise, the apparatus does not lend itself to incorporation in a relatively low cost multi-station exercise machine.
Some exercise machines have employed press arms with secondary pivots to provide the additional freedom of movement necessary for the operator to move his or her arms inwardly as the press arm is pushed outwardly. An example of such a device is shown in U.S. Pat. No. 4,949,951 issued to Deola. This patent discloses an exercise machine with a press arm having forward extension members that are coupled to the press arm with universal joints. The extension members permit the user of the machine to perform a "dumbbell fly" movement. Owing to the universal joint between the extension members and the press arm, the extension members will naturally fall towards the floor if let go. This is inconvenient for the user of the apparatus and, further, requires that the user exert an upward force on the extension members simply to maintain them in position for performing an exercise.
Another example of a prior art exercise machine is shown in U.S. Pat. No. 5,580,341 issued to Simonson. This machine for performing a shoulder press exercise has a pair of independent arms coupled to the machine by a primary hinge with a horizontal axis and respective secondary hinges. The design of the machine permits inward movement of the arms, but does not allow a true fly movement. The axes of the secondary hinges are preferably oriented at symmetric acute angles with respect to the primary hinge. This arrangement of the primary and secondary hinges operates to divide the exercise resistance into a longitudinal component and a lateral component. The lateral motion of the arms in Simonson's machine Is limited outwardly by an interconnecting strap and inwardly by respective stops. These stops preclude anything more than a straight press or inward press movement during performance of a press exercise. Since outward movement of the arms is prevented by the stops, a full fly movement cannot be performed.
Still another example of a prior art machine is the Freedom Chest Press manufactured by Pacific Fitness Corporation. In a manner somewhat analogous to Deola's exercise machine, the Freedom Chest Press has a pair of extension members pivotally coupled to the main press arm. The extension members pivot about respective secondary axes that are perpendicular to the main pivot axis of the press arm. Outward movement of the extension members is limited by respective stops, and thus, as with Simonson's machine, a full fly movement cannot be performed.
Each of these prior art devices has certain disadvantages which are overcome by the apparatus of the present invention. One of the objects of the present invention is to provide an exercise machine offering combined press and fly movements without the use of stops to limit the amount of fly movement available to the user. Another object of the present invention is to provide exercise arms for performing the combined press and fly movement exercises that have a gravity-induced natural rest position corresponding to the starting position for such exercises.